div {
	margin:10px;
	padding:5px;
}
#father {
	border:1px #000 solid;
	/* height:420px; */

}
.layer01 {
	border:1px #F00 dashed;
	float: left;
}
.layer02 {
	border:1px #00F dashed;
	float:left;
}
.layer03 {
	border:1px #060 dashed;
	float: right;
}
.layer04 {
	border:1px #666 dashed;
	font-size:12px;
	line-height:23px;
	width:100px;
	float: right;
}

/* .over{
	clear: both;
} */
#father:after{
    content: '';          /*在clear类后面添加内容为空*/
    display: block;      /*把添加的内容转化为块元素*/
    clear: both;         /*清除这个元素两边的浮动*/
}
